Crank-shaft connection for engines.



A. J. GIPPORD.

CRANK SHAFT CONNECTION FOR ENGINES.

APPLIGATION FILED AUG. 14, 1901.

Patented Aug. 24, 1909.

3 SHEETS-SHEET 1.

A. J. GIFPORD.

CRANK SHAFT CONNECTION FOR ENGINES.

APPLICATION FILED AUG. 14, 1901.

931,750. Patented Aug. 24, 1909.

3 SHEETS-SHEET 2.

Q TUE-EH65 5&5. k

A. J. GIPFORD.

CRANK SHAFT GONNEGTION FOR ENGINES.

APPLICATION FILED AUG.14, 1901.

Patented Aug. 24, 1909.

3 SHEETS-SHEET 3.

' sTAT-nsfiPATEN-r OFFICE.

ALItEBT J. GIFFOBD, 0F WORCESTER, MASSaCfifiS ETTS, ASSIGN O'R '10 CHARLES H. IEORGrAN,- 015 WORCESTER, MASSACHUSETTS.

CRANK-SHAFT CONNECTION mt ENGINES.

Toall whom it may concern: I

Be it known that I, ALBERT. J. -GIFFORD, a

citizen of the United States, residing at \Vorcester, in the county of iVoreester "and State of Massachusetts. have invented a new and useful Crank-Shaft Connection for Engines", of which the following is a specification.

This inventionrelates to a construction for. connecting an. engine piston, or a number of nectingl rt an engine constructed accordmg to th s nvention occuplcs a position substantiallyparallel.t-o the line of movement of the.v piston during the major part of the travel of the pistomso that during the time of highestteniperature and. pressure in the.

cylin er, and "during the time of highest piston traveling speed, there will be no side thruster pressure tending to crowd the piston againstthe side of its cylinder.

To these ends' this invention consists of the construction and combinations of parts, as hereinafter described,;and more particularly pointed; out inthe claims at the end of thisspecification. 1

In the accompanyin ings, Figure 1 is a section of an 'engineconstructed according .tomy invention. Fig. 2 is asectionalview of the-same taken on the line 2-2 of Fig. 1. Fig. 3 is a diagrammatic view illustrating threesheets of. drawthe relativeposltions occhpied by the parts, F g. 41s a-diagrammat-ic view illustrating the difierent angular positions of directly connected piston connecting rods of different lengths in ordinary practice, and Fig; 5 is a typical indicator diagram of an. explosive engine. i v

' In ordinary engine practice, in which the pistons are directly connected to their cranks by a connecting rod, the resulting angularity between the piston connecting-rod and the line of travel ofthe piston causes comparatively heavy lateral, pressures between the an view. partially in Specification ofLetters Patent. Application filed August 1 4, 1901. Serial No. 71,992.

. The lateral pressures between the piston and side cylinder walls of an engine greatly in crea'se'the difficulty of maintaining perfect fits and'satisfactory lubrication in the cylinder. These difficulties are especially noticeable in gas engines where high temperatures and pressures are produced in the engine cylinders, and Where great attention must be given to lubrication, inasmuch as the explosive mixture of gas and air frequently contains a considerable amount of dust and grit,

Patented Aug. 24, 1909.

for example, when explosive engines are sup plied with producer or blast furnace gas.

For good engine practice, where the piston and crank are directly connected, it is necessary that the connecting rod should be at least five cranks long. It is preferable if possible, to use a connecting rod even longer than this, the best practice frequently giving a connecting rod length of six cranks. 1n the use of a directly connected connecting rod five cranks long, the connecting rod will be and reaches its maximum during the second and third quarters of the piston stroke. Indicator diagrams from explosive engines, as illustrated for example in Fig. 5, show the pressures to. be very high throughout the second and third quarters of the stroke.

The especial'object of my present invention, is, therefore, to provide a form of connection which will reduce the total angular swing of the connecting rod, and which will have its centers of motion so located that the connecting rod will oecupy a position substantially parallel with the line of movement of its piston during the part of the travel of the piston .when the heaviest pressures are being transmitted thereby. To aceomplisl'i piston and the side xv'alls of the cylinder. i these objects, an engine constructed accordthe beam travels.

ing 'to my invention comprises one or more engine pistons, and a beamp voted at a point adjacent to the end of the cylinder or cylinders and between the end thereof and a line drawn perpendicular to the line of travel of the piston, through the centralpoint of the-curve on which the pivotal connection of the beam with the connecting rod travels whereby the connecting rod will be substantially parallel with the-line'of movementof' the piston during the first three quarters of travel of the piston;

Referring to the accompanying drawings, and in detail, I have illustrated my inven-r tion as applied to a quadruple cylinder'em gine of the type e'mp oyed for explosive or gas engines. It is to beimderstood,however, that my invention is applicable to othertypes of engines than the quadruple type herein illustrated.

Referring to said drawings, and in detail,

beam 14 carried by a rock-shaft .15, which rock-shaft 15 is provided with an arm 16- connected by a-pitman'17- to turn .the crank 18 of the main shaft H. These parts .mayEbe of substantially the ordinary construction which have been employed in engines'of this class, except that thepivot of theb ea'm 14, or axis of the rock-shaft 15, islocatedoutof line with, and betweenthe end of the cylinder and a'lineoonnecting' the points at which the conne'ctingirods 13'are'attached to the beam. It willbe seen also that theaxis of the rock shaft 1'5'isat' a point adjacent tothe end of the cylinder and betweenfs'aid' end and-a horizontal line drawn'from the central point of the are through which the end of The arms of the pivoted beam are of such a length, that the connecting rods 13 will have only a slight outward inclination when in their highest position.

The relative angular movements of the parts as I preferably construct them is most clearly illustrated in Fig.3. I preferably arrange the parts so that the piston connecting rod will have an-angularity of about one degree at the instant of explosion, when the maximum pressure of "nearly two hundred and fifty pounds to the square inch is applied to the piston. When the piston having a stroke of twenty inches has traveled five inches, or the first quarter of its stroke.

the angularity of-"the piston rod will have increased to about one and three-qu arters degrees, after which it will decrease, so that; when the piston has traveledeleven and one-half inches, the connecting rodwill occupy an exactly vertlcal position. In the last part of the stroke of the piston, the

piston 12,

der pressure the other side" until it amounts toabout eight degrees at the end of the twenty-inch stroke.

'1heincreasing angularity of the connecting*- rod during the very lastparti of the stroke of the piston is of no disadvantage whattravel are at a minimum duringthis part of the movement. In

wide open during allof thelast quarter of v v fact-,inmam as engine constructions, the exhaustrehef passage is angulariy of the connecting rod increases on I the piston travel, so'that during. this partof themovem'ent no'workingipressure is main} tained' in the cylinder-.

, I amawarethat changesmay be made in the relative proportion and arrangement of parts without departi'ngffronr the scope of my invention as expressed in the claims. I

do not wish, therefore, to be limited to the construction herein sl'i'oi'v-n, but

7 What I do clainr and desiretosec'ure by Letters Patent of the United States is l. Ina piston compression gas engine, the combinationof a pivotally' mounted beam,

two engine pistons, piston'conneeting rods connecting said. pistons directly tothe ends of the beam, th'epoint' at'whi'cnthebeam' is pivol'ed being located;materially at the side town rd the pistons of a; line connecting the points of attachment of i the'piston connecting rods with the beam whereby the piston connecting rods will each occupy positions substantially parallelw-ith-the'line of movement of their pistons during the greater part of their stroke while the pistons are unof explosion, and also during the greater part of ,the return stroke thereof while the fresh charge is being compressed. i 2. In a'piston compression gas engine, the

combination of;'a pivotally mountedbeani, an engine pistonmovable vertically to compress a charge, a cylinder therefor, and rneanfs'for' connecting the end of the beam with the piston, said beam beingp'ivoted at a omt adjacent to the end of the cylinder an between the end of the cylinder and a horizontal line drawn from the'central point of the travels.

3. A piston compression gas'engine of the are through which theend of the beam type having a piston, a cylinder, abeam, and i a connecting rod pivotally connected di- .r'ectly with'the'piston and with thebeam, in

which thebea-m is pivoted at a point between the end of the cylinder and a line Y drawn perpendicular to the line oftr'avel of the piston, through the central point of the curve onwhich the pivotal connection of the beam with the connecting rod'travels, whereby the rod is located at a slight an-gleto'the axis of the piston at the beginning of the working stroke, the angle being'slightly increased during the first part ot the working stroke, then gradually decreasedtozerountil the rod is brought across said axis during In testimony whereof I have hereunto set the third quarter of the stroke and the angle my hand, in the presence of two subscribing of the rod is materially increased on the witnesses.

other side of the axis, said operations being ALBERT J. GIFFORD. reversed during the corresponding parts of Witnesses:

the return stroke occupied by a compression LOUIS W. SOUTHGATE,

of a fresh charge. PHILIP W. SOUTHGATE. 

